Plasmonic metasurfaces with scalable quasi-orders for optical security

Abstract

Inspired by nature's quasi-ordered structural colors, we develop cost-effective plasmonic metasurfaces that generate stable optical responses with unique, unclonable scattering fingerprints. Building upon our previously demonstrated gold-based plasmonic physically unclonable functions (PUFs), this study advances toward scalable and industrial implementation by replacing the costly gold mirror with aluminum. Through a single-step electrostatic assembly, quasi-ordered gold nanoparticles are self-assembled on an aluminum mirror with an ultrathin oxide gap, forming metasurfaces that maintain high-entropy scattering. We fabricate and analyze 40 PUF keys, which demonstrate high uniqueness and optical readability, highlighting their potential as reliable hardware security primitives. This approach offers an economically viable and industrially compatible pathway for next-generation anti-counterfeiting and identification technologies. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.